Run results for: clientHeight vs offsetHeight vs window.getComputedStyle

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:81.0) Gecko/20100101 Firefox/81.0

Browser: Firefox 81

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
clientHeight	2124240.0 Ops/sec
offsetHeight	2331393.0 Ops/sec
window.getComputedStyle	1205134.0 Ops/sec
Multiple: Only _style	447885.0 Ops/sec
Multiple: _style e clientHeight	509096.3 Ops/sec

HTML Preparation code:

<div id="teste">teste</div>

Script Preparation code:

var teste_n = '123px';
var _style = window.getComputedStyle(document.getElementById('teste'));

Tests:

clientHeight
document.getElementById('teste').clientHeight;
offsetHeight
document.getElementById('teste').offsetHeight;
window.getComputedStyle
parseFloat(_style['height'])
Multiple: Only _style
parseFloat(_style['margin-top']) parseFloat(_style['margin-bottom']) parseFloat(_style['height'])
Multiple: _style e clientHeight
parseFloat(_style['margin-top']) parseFloat(_style['margin-bottom']) document.getElementById('teste').clientHeight;